Delhi’s air pollution is so severe that it’s sometimes hard to discern anything more than a few metres ahead. And it’s affecting people’s health. Breathing becomes uncomfortable, and one of us (Komali) developed rashes and red eyes on a recent trip to the city.
Our experiences are not unusual. Delhi – officially the National Capital Territory of Delhi – is the world’s second-most populated urban area and one of the most polluted.
National Capital Territory recently exceeded the healthy limit prescribed by the World Health Organization by 26 times.
The Air Quality Index, or AQI, is a measure of how polluted the air is, on a scale of 0 (clean) to 500 (maximum pollution). On November 19, Delhi’s average AQI was 485.
Many of its air pollution sensors maxed out at 500, so the true figure would be even higher.
Things peak every winter when many people suffer from respiratory problems and hospital visits increase.
An extraordinary 11.5% of all deaths in the city can be attributed to air pollution, leading to a loss of around 12,000 lives every year.
A human-made calamity This is a human-made calamity with many causes. Some factors are common to many large and fast-growing cities, especially in emerging economies.
Delhi has many coal power plants, for instance, and its streets are choked with heavy traffic. Decades of dust, often from the construction industry, have accumulated in and around the city. Waste is often simply burned.
Burning field
But some factors are more specific, and it is these that push Delhi from “regular pollution” into catastrophe.
Every year, farmers across northern India, especially in the breadbasket states of Punjab and Haryana, burn unwanted straw left behind in fields, sending huge clouds of smoke downwind towards Delhi. Fireworks during Diwali (held on October 31 this year) also cause a small but noticeable increase in air pollution.
All this is exacerbated when winter begins, and colder, more polluted air becomes trapped over the city by a layer of warmer air above it – a process known as temperature inversion.
A conscious effort The risk of pollution is increasing. Central and state authorities blame each other, and there is a lack of political will to address the problem. Individual people seem unwilling to take responsibility and stop polluting.
A conscious effort is needed. Fortunately, certain policies could make a difference. Materials should be covered at construction and demolition sites, for instance, to prevent so much dust from being blown into the air.
This may require Delhi to strengthen its legal enforcement system.
Dusty construction site
The city should plant more pavement trees and create new parks. Trees are good at combating air pollution. Waste burning should be restricted. Eventually, coal power will need to be replaced by wind and especially solar energy.
When pollution is at its worst, the city can impose strict restrictions on large diesel-powered freight vehicles transporting non-essential items.
Farmers, for their part, must stop burning plant material left behind (known as stubble) after food is harvested. This is easier said than done.
The areas upwind of Delhi tend to have two growing seasons, and many farmers burn off their rice stubble in November before planting wheat in the same field.
The system has persisted for a long time and is effectively locked in, with most powerful actors not having enough incentive to change things.
There are some alternatives. Farmers could be encouraged to diversify their crops, perhaps through conditions attached to loans.
Some of that stubble could instead be used as cattle feed, in compost, as a roof material, or burned in bioenergy plants to produce electricity.
Evidence-based strategies and best practices are crucial. The goal must be to reduce the air quality index to the “good” category of 0–50 and ultimately to eliminate toxic air in Delhi and the surrounding region.
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